Adaptive processing method of clutter rejection in a phased array beam pattern

• US 7,728,769 B2
• Filed: 03/12/2008
• Issued: 06/01/2010
• Est. Priority Date: 03/12/2008
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Kennedy, William, Chang, Kaichiang
• Primary Examiner(s): Issing; Gregory C
• Application Number:
  US12/075,510
• Publication Number:
  US 20090231195A1
• Time in Patent Office: 811 Days
• Field of Search: 342/360
• US Class Current: 342/360
• CPC Class Codes: G01S 2013/0254 Active array antenna
• CPC Class Codes: G01S 7/414 Discriminating targets with respect to background clutter
• CPC Class Codes: H01Q 21/22 Antenna units of the array energised non-uniformly in amplitude or phase, e.g. tapered array or binomial array
• CPC Class Codes: H01Q 3/2605 Array of radiating elements provided with a feedback control over the element weights, e.g. adaptive arrays

Abstract

An adaptive processing method of and system for clutter rejection in a phased array beam pattern. The amplitude distribution of the transmit elements of a two-dimensional phased array is determined. A desired pattern with low side lobes for a linear array is synthesized. The amplitude distribution of the transmit elements of the two-dimensional phased array is compared with the synthesized pattern. Select elements of the two-dimensional array are disabled to best fit the determined amplitude distribution of the transmit elements of the two-dimensional phased array to the synthesized beam pattern. Phase only pattern synthesis is performed to produce a desired two-dimensional beam pattern with low side lobes to minimize any best fit errors.

Claims

1. An adaptive processing method of clutter rejection in a phased array beam pattern, the method comprising:

determining the amplitude distribution of the transmit elements of a two-dimensional phased array;

synthesizing a desired pattern with low side lobes for a linear array;

comparing the amplitude distribution of the transmit elements of the two-dimensional phased array with the desired pattern;

disabling select transmit elements of the two-dimensional array to best fit the determined amplitude distribution of the transmit elements of the two-dimensional phased array to the synthesized beam pattern; and

performing phase only pattern synthesis to produce a desired two-dimensional beam pattern with low side lobes to minimize any best fit errors.

2. The method of claim 1 in which the desired beam pattern is a Cosecant-squared beam pattern.

3. The method of claim 1 in which the desired beam pattern is formed by a two-dimensional array having an arbitrary configuration including blockages and voids produced by auxiliary antennas and dummy elements.

4. The method of claim 1 in which the desired beam pattern is formed in real time to heal element features for high reliability.

5. The method of claim 1 in which the desired beam pattern is an arbitrary pattern with a deep spatial notch for electronic counter countermeasures.

6. A phased array radar system comprising:

a plurality of transmit and receive modules each selectively enabled; and

a beam steering generator which controls the phase of the transmit And receive modules, the beam steering generator configured to;

determine the amplitude distribution of the transmit and receive modules,

synthesize a desired pattern with low side lobes for a linear array,

compare the amplitude distribution of the transmit and receive modules with the desired pattern,

enable select transmit and receive modules to best fit the determined amplitude distribution to the synthesized beam pattern, and

perform phase only pattern synthesis to produce a desired two-dimensional beam pattern with low side lobes.